An in-depth interview entails a detailed, thorough interview with a respondent on a given topic. During the interview, a qualified researcher follows a thematic plan constituting an interview scenario.
The purpose of the interview is to broaden the knowledge on the topic of particular interest or relevance by asking exploratory questions to explain and understand the issue in question. For this reason, an important aspect of the interview is ensuring the unrestricted freedom of expression, as well as conducting the conversation in such a way that all surveyed issues are addressed.
An in-depth interview is often used to address difficult or personal topics, such as illness or addiction, or when a negative effect of the group on respondents’ statements may be expected or when confronting the opinions of respondents is not required. IDIs are also useful when interviewing difficult-to-reach groups such as experts or people holding prominent positions or at geographically dispersed locations.
For in-depth interviews, assisting and projection techniques which involve visual materials or associations may be used to allow for an thorough interpretation of the respondent’s statements. In-depth interviews provide for exploration of personal experiences, mechanisms and motives of decision making process, but also precisely describe the causes of actions, opinions and attitudes towards products and services, as well as help understand the respondent’s perception of social phenomena or a brand.